How long is the protection period of patented drugs?

A drug patent can only be an invention patent. According to the Patent Law of People's Republic of China (PRC), the protection period of an invention patent is 20 years. In Article 42 of the Patent Law of People's Republic of China (PRC), the term of the invention patent right is 20 years, and the term of the utility model patent right and the design patent right is 10 years, all of which are counted from the date of application.